$ { {3} \times \left[\begin{array}{rr}{4} & {-2} \\ {-2} & {2}\end{array}\right] = {?} } $
Answer: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{3}\times{4} & {3}\times{-2} \\ {3}\times{-2} & {3}\times{2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{12} & {-6} \\ {-6} & {6}\end{array}\right]}$